The invention relates to gaskets used to seal the mating surfaces of parts comprising an internal combustion engine.
The prior art teaches the use of a plurality of sealing elements, characteristically formed of elastomers, cork or rubber, to seal the gap between engine components where the large mating surface therebetween makes it impossible or uneconomical to cut a gasket therefor from a single sheet of gasket material. It is difficult, however, to maintain proper alignment of a multiplicity of sealing elements during assembly of the engine components. Moreover, the individual elements typically move from their properly aligned positions while the engine component surfaces to be conjugally secured are forcibly clamped together as by the tightening of threaded fasteners. Leak paths between adjacent sealing elements are likely to be created by such misalignment, thereby rendering the seal ineffective.
The prior art also teaches the use of a gasket comprised of a single custom-molded elastomeric sealing element. The leak path problem is thus avoided. The onepiece gasket may additionally employ internal stiffening means, such as incorporating a metal sheet therein, to prevent lateral displacement of the gasket upon clamping of engine components. However, as the one-piece seal is custom molded for each application, it is much more costly than its multiple element counterpart. Further, the one-piece seal remains subject to leaking where improperly aligned during installation.